The artist usually known as Jennifer Lopez will unveil her new alter-ego, “Lola,” at Miami’s Fontainebleau tonight. J. Lo will debut her new music video, “Fresh Out of the Oven,” featuring Pitbull at the hotel’s LIV nightclub. Sources say Lopez created the character — the way Mariah Carey created “Mimi” — for her new dance track, but she won’t stay as Lola full-time.